The culturing of sugpo (Penaeus monodon Fabricius) in the Philippines has been
carried out for a very long time in association with the culturing of bañgos (Chanos
chanos). They were grown simultaneously in the same fishponds, with sugpo as a secondary
product; it was never raised alone. With the exploitation of the sugpo fry fishery,
the more lucrative business of pure sugpo culture has developed.

The sugpo fry are caught commercially along the shores of Manila Bay from the early
part of May until the end of October or early November, but in other places the fry
enter fishponds with the incoming high tide. Different methods of catching fry, the
selection of a site for cultivation, the construction and preparation of a pond, and the
raising and harvesting of sugpo are described.

In spite of problems encountered in the culturing of sugpo, a comparison of the
production of a pure bañgos culture, a mixed bañgos and sugpo culture, and a pure sugpo
culture, shows that the latter gives the highest net income.

The culturing of sugpo (Penaeus monodon Fabricius) in the Philippines is as old as
the culturing of bañgos (Chanos chanos Forskal), but sugpo was grown as a secondary product
and was never raised alone. In many places in the Philippines, as in Mindanao
and parts of southern Luzon where ponds are established near the probable breeding
places of prawns, the fry just enter the fishponds and are continuously harvested.

Since sugpo fry are readily recognizable from other fry, their collection and commercial
exploitation was developed and led to the sugpo fry fishery. This is now a
distinct and lucrative fishery in many places in the Philippines, especially in the
coastal towns of Cavite and Batangas, where they are caught from May to October.

Villadolid and Villaluz (MS) described the cultivation of sugpo with bañgos and
separately.

The sugpo fry generally appear along the shores of Manila Bay in the early part of
May and continue until the end of October, sometimes extending to the early part of
November. They are easily distinguishable by the dark brown pigment running through
their transparent bodies, thus making them appear like small pieces of broken stick or
debris. They usually measure from 10.0 to 15.2 mm. Delmendo and Rabanal (1956) gave
the length of fry as 15.3 mm, but the latest sugpo fry surveys in Ternate, Cavite,
(Caces-Borja, MS) have revealed some as small as 8 mm, much smaller than previously
reported.

2.2 Fishing grounds

The fry are caught in almost all places in the Philippines where bañgos fry are
found. In the northern parts of Luzon, sugpo fry appear rather later than the bañgos
fry. The practice in the region is to gather the sugpo fry only when there is a demand
for it.

Sugpo fry can also be found in tidal rivers, creeks, lagoons, and other shallow
places with brackish water where they are brought in by the incoming high tide. They
have been found attached to masses of drifting seaweeds. They also cling to various
aquatic plants, such as the water hyacinth and lily, and semiaquatic plants of the
family Gramineae which grow in swampy places below the tideline. They are found particularly
after storms, which usually occur in the months of June, July and August.
The sugpo fry migrate to the shore and into brackish waters for feeding and shelter.
They remain in these places for not less than 6 mo, after which they return to the sea
to spawn.

The Maragondon River contains fry of various sizes, and some early adults of up to
80 mm are caught further up the river, showing that the fry metamorphose in the river
(Caces-Borja, MS). This is the largest river emptying into Manila Bay and apparently
attracts and accumulates fry in their fresh water migration after having been hatched
in the deeper, more saline waters just outside the Bay. Fig. 1 shows the Maragondon
River, with its mouth in Manila Bay divided by Balut Island. The peak of the fry
season occurs during the months of September and October with the northeast monsoon.

All along the western coast of Luzon, sugpo fry are found during the bañgos fry
season.

The most important sugpo fry grounds surveyed by the Agricultural Department of
the Development Bank of the Philippines are listed below:

Dagatdagatan Lagoon, Malabon, Rizal Province

Dongalo River, San Dionisio, Parañaque, Rizal Province

Binuangan River between Tanza, Navotas, Rizal and Obando, Bulacan

Mabolo River and Nalamok in Bacoor Bay and in Salinas, Tanza, Cavite Province

Binangbang River and other tributaries along the shores of Balayan Bay and along the shores of Sta. Clara, Batangas, Batangas Province

Tributaries along the shores of Pagbilao Bay and Tayabas Bay, Quezon Province

Tributaries along the shores of Pitogo and Macalelon, Quezon Province

Cabilihan River extending from Guinayangan, Tagkawayan and Calauag, Quezon Province.

Fig. 1 Map of a portion of Manila Bay showing the Maragondon River
where there is an abundance of sugpo fry.

2.3 Collection and marketing

Sugpo fry are caught in several ways. The use of fish lures, locally called “bonbon”,
is an easy method. The “bon-bon” is made of bundles of twigs or grasses tied to
a long line of rattan, wire, or string at intervals of about 1 to 2 m. The common
species used for this purpose is a salt-water grass, Paspalum vaginatum. Several lines
of these lures are set up in the water by tying the opposite ends to wooden poles near
the bank of the river at intervals of 10 to 20 m. The fry collectors then visit their
lures and place their dip net beneath each bundle of grass. They raise and shake each
bundle to catch the clinging sugpo fry into the net. Some experienced collectors are
able to gather as many as 10 fry from one bundle at a time. During the peak of the
season, one could gather as many as 1,000 fry in 1 h. Collections are also done at
night with the use of flashlights. This is the usual method employed in the provinces
of Batangas, Cavite and Rizal (Fig. 2).

Another method is by dip net. The collector gathers the fry by dipping a triangular
net into the water, while sitting in his wooden ‘banca’ or dugout. From the net
the fry are transferred to an earthenware jar by scooping them up with a white porcelain
bowl. The jar is provided with a few shredded banana leaves for the sugpo fry to cling
to. Fry are collected at least twice a day, regardless of the tide or weather (Fig. 3).

Some collectors sort their fry during collection to remove unwanted species and
store the sugpo fry in lots of 100 to 250 in earthenware pots. The fry are later distributed
to fishpond owners. The old practice was to transport fry in the same pots
in which they were stored, but now the use of plastic bags is very popular because of
their handiness and light weight (Caces-Borja, MS). These bags are half-filled with
sea water and closed with elastic bands at the mouth. Then they are packed into ‘buri’
bags for easier handling. When they have to be transported for longer distances, the
bags are aerated by the use of a bicycle pump.

The fry are sold at P13 to P35 per thousand depending on their abundance.1 During
the height of the fry season in Ternate, Cavite, the price is as low as P13 per thousand.
In Batangas, the sugpo fry dealers maintain their price of P25 per thousand throughout
the whole season. In Dasol, Agno and Bolinao, Pangasinan Province, sugpo fry sells
from P20 to P30 per thousand, with the peak price in August and September. This is the
only place in northern Luzon where the catching of sugpo fry is commercialized. In
La Union, there is no pure sugpo fry business; they are caught along with the bañgos
fry during the months of February to July, and sell for only P10 per thousand.

Surveys made in 1965 on behalf of the Development Bank of the Philippines in cooperation
with private fishpond operators have studied current fishpond practices in
the cultivation of sugpo. The report notes the following important factors to be considered
in the selection of a fishpond site:

Source of water

The availability of water supply is very important. There should be an available
supply of fresh, brackish and salt water, depending upon the stage of growth of
the shrimp. Fresh water has been found more favorable during the early stages of
development, while brackish to saline waters are conducive to faster growth in the
later stages.

Type of soil

Areas with sandy clay to clay loam are preferable for construction and for good
growth of algal food, while sandy clay suits the creeping and burrowing habit of
the sugpo.

Elevation

The area should be within the reach of ordinary tides to be easily filled to a
depth of at least 3 ft. Ponds with elevated bottom should be excavated so that
they could be filled during the dry season when tides are low.

3.2 Constructing the pond

Delmendo and Rabanal (1956) described a model layout for a 10 ha Penaeus pond project
as shown in Fig. 4. The whole area is enclosed by a main dike with a concrete
main water control gate (mg), of double-opening type, placed at a point easily accessible
to the main portion. This should open into a head pond (hp), which should be the
deepest portion of the system.

The whole area may be partitioned into the head pond (hp), two nursery ponds (np),
together occupying 1 ha, and two rearing ponds (rp) of 4.5 ha each. The rearing ponds
open to the head pond by two secondary gates (sg).

The entire fishpond system should be so levelled that the bottom gradually slopes
from the periphery to the head pond and to the main water control gate. A system of
special depressions or canals is constructed in each nursery and rearing pond, running
from the periphery towards the head pond, through the secondary gates, as indicated in
Fig. 4. These canals facilitate harvesting.

3.3 Preparing the ponds

Villadolid and Villaluz (MS) described the preparation of a sugpo fry nursery pond,
usually the smallest compartment in a brackish-water fishpond system. Each pond is
built with wooden gates, 1.5 to 2 ft (0.5 to 0.7 m) wide, provided with wooden slabs for
water control, and with fine-meshed bamboo screens covered with abaca cloth (sinamay) to
prevent the entrance and exit of sugpo fry as well as predatory species. Current practices
make use of nylon screens instead of sinamay for durability. After cleaning and
levelling the bottom, the nursery ponds are dried for a period of 4 to 6 wk, depending
on weather conditions. Then, tidal water is let into the pond to a height of from 3
to 10 cm to induce the growth of ‘lab-lab’ (microbenthos) which will serve as the food
of the young fry. New tidal water is let in to maintain the original height of the
water. In about a month the nursery pond is ready for stocking.

Fig. 4 Model layout for a 10 ha Penaeus pond project.

Delmendo and Rabanal (1956) stated that there was no standard method of raising
sugpo in ponds. Shrimp cultivation is generally considered as a supplementary source
of income and seldom are special ponds set apart for this purpose. However, the best
results have been observed to stem from previously prepared nursery ponds for sugpo.
The preparation of these nurseries for sugpo follows the same procedure as in Chanos
culture, that is by cleaning, levelling, draining and drying the bottom. Then ‘lab-lab’
is grown on the pond bottom, and the pond is ready for stocking.

Current fishpond practices give great importance to the preparation of the ponds.
According to technical information from the Development Bank of the Philippines, which
gives loans for sugpo culture, things to be done are:

Clearing

The fishpond should be cleared of unnecessary vegetation to assure maximum sunshine
to enhance better growth of both the bluegreen algae (included in ‘lab-lab’)
and the filamentous green algae (‘lumut’). Short branches and twigs of swamp trees
should be installed on the pond bottom to provide shelter or refuge from enemies
as well as a place for attachment.

Gates and dikes

The area should be provided with a strong concrete main gate, so that tidal water
may frequently be allowed to flow in and out of the ponds to provide aeration,
especially in the evenings. The area should be surrounded by a sturdy main dike
capable of withstanding water pressure while maintaining 3 ft (0.9 m) of water within
the ponds. Provisions for proper installation of bamboo screens (‘baklad
pahasang’) should be made with nylon or sinamay nettings whenever necessary to prevent
the possible escape of stock and the entrance of predatory species.

Levelling, liming and fertilizing the pond soil

The entire fishpond bottom should be levelled in such a way that it slopes gradually
from the periphery toward the water control gate. The liming of the pond bottom
at the rate of at least 10 bags of agricultural lime per ha is needed to obtain
good results in sugpo culture. The lime serves to absorb excess carbon dioxide
in the water, as well as to supply the necessary calcium needed by the shrimps, especially
during their molting periods. Fertilization with inorganic commercial
fertilizers may be practised but not with organic manures.

Eradication of predators

It is necessary to clear the ponds thoroughly of predatory species before stocking,
because sugpo are prey to carnivorous fishes and other predators due to their
clinging and sluggish habits. Methods have been described by Villadolid and
Villaluz (MS) and Delmendo and Rabanal (1956).

3.4 Raising the sugpo

Two ways of culturing sugpo are employed: (i) the usual way of a mixed culture
with bañgos, and (ii) the more recent way of pure culture, i.e. only sugpo fry are
stocked in the ponds.

In a mixed culture, the sugpo fry are planteu in a pond that has already a stock
of bañgos fry. This is to prevent predation on the bañgos fry. Stocking is done
during the cooler part of the day in order to minimize the effect of a sudden change in
temperature.

Pure culture is being practised by a few fishpond owners operating large areas of
fishponds. In stocking the fry, care is taken to distribute them as evenly as possible
over the pond. Sugpo fry, when newly stocked in a pond, do not wander about immediately
in search of food. They remain where they are liberated and become easy prey to any
predaceous species that might come upon them.

The stocking rate in the nursery pond is 300,000 to 500,000 fry to 1 ha in pure
culture. In the rearing pond, the rate of stocking depends upon the availability of
food. The fry are kept in the nurseries for a period of 1 to 1½ mo, after which they
are transferred to the rearing ponds. A pond with good growth of ‘lab-lab’ and provided
with supplementary feed of animal protein can be stocked with 2 sugpo per m2,
or 20,000 per ha. However, the ordinary practice of fishpond owners is to stock the
rearing ponds with 1 sugpo per m2, or 10,000 per ha.

The food of the sugpo consists of ‘lab-lab’, a biological association of minute
plants and animals growing on the mud floor of fishponds. Rabanal (1952) made a comprehensive
analysis of the components of ‘lab-lab’, identifying many types of fungi,
bacteria, diatoms, algae and small animals.

In addition to the ‘lab-lab’, supplementary feeds are given. These consist of
dead fish, dead animals and small crabs, which are ground into meal and piled in a corner
of the pond. This serves partly as food and the unconsumed portion serves as fertilizer.
Another method of supplementary feeding is to dip miscellaneous small fishes
in boiling sea water, to soften the flesh, and place along the sides of the dike where
the sugpo start feeding late in the afternoon or evening.

Rice bran is also used as a supplementary food for the sugpo fry. Filamentous
algae are not allowed to grow in the nursery ponds, to prevent entanglement of the fry
among the filaments. Instead, small bundles of dried twigs are placed to provide something
for the fry to cling to during their early weeks of life. Sampling is also made
easy by simply raising the twigs and collecting the attached fry. Villadolid and Villa
luz (MS) stated that after the sugpo have attained a length of about 54 mm they lose
their clinging instinct.

After a period of 1 to 2 mo, during which the sugpo fry have grown to a size that
can be transplanted to the bigger rearing ponds, shrimp traps are set to catch the sugpo.
These traps are made of bamboo screens of ‘baklad’ set in the pond bottom. There
is a leader or guide screen, a forechamber, and a catching chamber or cod end. The
shrimps seem to have no schooling habits and do not all enter the traps. Those left
are picked out of the mud, after draining the pond slowly to allow the shrimps to go to
the deeper areas. The young sugpo are now transferred to the bigger rearing ponds.
In cases where the nurseries are adjacent to the rearing ponds, a portion of the dike
that separates the ponds is opened and the sugpo are driven through the opening by disturbing
the pond and scaring them. The rearing ponds are provided with ‘lumot’ or
filamentous green algae which serve as the food for the bañgos and the sugpo.

Studies being undertaken by the Philippine Fisheries Commission on the food of the
sugpo have shown a better growth and higher survival rate among sugpo fed with fish
flesh in different forms, i.e. raw, blanched or powdered. Although the data gathered
in these feeding experiments have not been thoroughly analyzed, a cursory inspection of
the results showed a greater size increase in those with animal protein in their diet
than those fed only with the natural food in the fishpond.

The sugpo under cultivation attain marketable size in a period ranging from 5 mo
to 1 yr.

A study on the rate of growth of sugpo in ponds was undertaken at the Dagatdagatan
Salt-Water Fishery Experimental Station, Malabon-Navotas, Rizal, covering the periods
from September 1943 to April 1944 and September 1950 to August 1952 (Delmendo and Rabanal,
1956). It showed that the sugpo which had been raised in ponds for 1 yr measured
on the average 229.8 mm in total length and 32.0 mm in body depth and weighed 95.1 g.
The largest specimens of this age may, however, be as long as 250 mm and weigh about
120 g, while others may be as small as 180 mm long with a weight of 50 g. A kg of 1 yr
old sugpo may contain 8 to 20 individuals. Table I shows the average rate of growth
of Penaeus monodon under cultivation.

TABLE I

Average rate of growth of Penaeus monodon under cultivation

Duration of Culture

Total length (mm)

Body depth (mm)

Weight (g)

Fry

15.3

1.6

0.025

1 week

21.5

2.5

0.06

2 weeks

28.2

3.6

0.08

3 weeks

38.8

4.5

0.92

4 weeks

45.3

5.7

0.78

5 weeks

57.1

7.8

1.63

6 weeks

60.3

9.7

3.39

7 weeks

69.5

10.9

4.36

2 months

79.0

9.8

4.34

3 months

94.7

11.1

6.88

4 months

120.0

15.3

14.5

6 months

141.9

18.3

22.3

7 months

152.6

16.4

25.1

9 months

178.0

27.8

57.3

10 months

211.6

30.2

62.8

11 months

223.0

32.0

70.7

1 year

229.8

32.0

95.1

3.5 Harvesting

Harvesting the marketable sugpo from the rearing ponds is a difficult job because
of their burrowing habit and non-gregarious instinct. Some loss is suffered in this
operation because of their habits, although different methods of capture are employed
to minimize this loss.

Delmendo and Rabanal (1956) described three different types of bamboo screen traps,
namely the ‘bakikong’, the ‘paabang’ and the ‘aguila’.

The ‘bakikong’ has a leader consisting of 1 or 2 bamboo screens staked and oriented
perpendicularly or diagonally from the pond dike which leads the shrimp to a forechamber
from which the shrimps are led into the cod end or catching chamber. A light is installed
in the catching chamber at night to attract more catch. This type is especially
effective during dark nights, particularly if there is water movement caused by renewal
or draining.

The ‘paabang’ consists of the catching chamber, which is centrally located, and
2 wings to screen the water passage. This is set to intercept the shrimp at some narrow
gap in the fishpond system. This type is especially designed for dark nights and
when strong currents of water can be made to flow through the passage where they are set.

The ‘aguila’ is a modification of the ‘bakikong’ consisting of a leader, comparatively
longer than that of the ‘bakikong’ and 2 chambers strategically located at both
sides at the end of the leader. This is set in the deepest portion of the pond and
the catch is more or less continuous regardless of the time of day or night or whether
or not the flow is regulated.

Besides the bamboo screen traps, net traps are also used. A bag net of coarse
cotton twine, mounted on a wooden frame, fitting into special grooves in the gate, has
come into general use in the cropping of shrimps in ponds. This net is called the
‘lumpot’. It is a sort of bag net tapering to an open end which is closed by tying
with a piece of string. It is usually set at the main control gate, the water being
previously raised to the maximum height at high tide. Thereafter, at sundown the water
is allowed to go out with great force. The shrimps are carried by the current
the end of the bag where they are collected from time to time by a man stationed on a
dugout canoe.

The most important problem facing the sugpo industry is the apparent lack of fry
for stocking. The known sources of sugpo fry are good only for certain months of the
year and are not enough to meet the demands of fishpond operators. This is the main
reason why many operators will not venture into the pure culture of sugpo.

A preliminary survey of the sugpo fry resources in the country shows a seasonal
abundance of fry in certain areas. However, the fishery is not always exploited for
several reasons:

There is no market; these places are often out of reach of operators and are
not generally known

The people in the community lack the technical skill for gathering or collecting
fry

The people in the community are engaged in other occupations like rice-farming

Sugpo fry cannot be recognized from other kinds of shrimp

4.2 Low rate of survival

A second problem is the low rate of survival of the sugpo. On average, the rate
of survival, based on the amount of marketable sugpo recovered from fishponds, is 20
percent. This could be due to the food, presence of predators, natural mortality or
the non-recovery of some due to their burrowing habits. Some fishpond operators, however,
have recovered as much as 60 percent from rearing ponds stocked at 10,000 fry per
ha. These operators have given supplementary feeds to their stock.

4.3 Difficulty of cropping

A third problem is the difficulty of cropping. During cultivation, the sugpo are
cropped twice, i.e. at the time of transfer from nursery to rearing ponds and at harvest
time for the market. The methods employed are not yet good enough to effect a total
catch because of the burrowing and non-gregarious habits of the sugpo. These have still
to be improved.

Observations made by technical men of the Development Bank of the Philippines,
Agricultural Department, on actual practices in the cultivation of sugpo, show that
1 ha of nursery pond with sufficient food supply can accommodate as much as 500,000
sugpo fry. In the rearing pond, the rate of stocking should be 1 sugpo for every m2
or at least 10,000 sugpo per ha in the case of pure culture of sugpo, and 1 sugpo for
every 2 m2 in the case of a mixed culture of bangos and sugpo.

Assuming 50 percent survival from the time of cultivation in the rearing pond to
the time they are harvested, 1 ha of fishpond (in the case of pure culture of sugpo)
can yield about 5,000 marketable sugpo, equivalent to 250 kg (20 to 1 kg) valued at
P1,250 based on the wholesale price of P5.00 per kg.

In a mixed culture of bañgos and sugpo, 1 ha of pond will yield about 1,000 marketable
sugpo (based on 20 percent survival) equivalent to 100 kg valued at P500.00 (based
on P5.00 per kg).

Table II shows the comparative production yield from 1 ha of fishpond with respect
to the three types of cultivation, namely: (i) pure culture of bañgos, (ii) mixed culture
of sugpo and bañgos, and (iii) pure culture of sugpo.

With the cost of 1 sugpo ranging from P0.02 (fry stage) to P0.05 (juvenile stage),
marketable-sized sugpo cost from P3.50 to P6.50 per kg, depending on their quality and
size. The market value is highest during the Holy Week and Christmas seasons, when
1 kg costs from P7.50 to P9.00. A pure culture of sugpo would certainly give a bigger
annual income than either a mixed culture of bañgos and sugpo or a pure culture of
bañgos alone.

Mane, A.M., D.K. Villaluz and H.R. Rabanal, 1952 Cultivation of fish in brackish and estuarine
waters in the Philippines. In Philippine Fisheries Handbook, prepared
by the Technical Staff of the Bureau of Fisheries, Manila,pp. 132-41